class_docstr: Displays a progress bar.
  
  Arguments:
      target: Total number of steps expected, None if unknown.
      width: Progress bar width on screen.
      verbose: Verbosity mode, 0 (silent), 1 (verbose), 2 (semi-verbose), 3 (compact table)
      stateful_metrics: Iterable of string names of metrics that should *not* be
        averaged over time. Metrics in this list will be displayed as-is. All
        others will be averaged by the progbar before display.
      interval: Minimum visual progress update interval (in seconds).
      unit_name: Display name for step counts (usually "step" or "sample").
code: def add(self, n, values=None):
      self.update(self._seen_so_far + n, values)
  
imports: import copy
  import os
  import sys
  import time
  import numpy
  from .callback import Callback
label_desc: Use image node_id 3 for calling the Progbar obj's underlying member method code with example usage: obj.add(n, values) without return types